The present invention relates to power semiconductor devices and more particularly to a III-nitride power semiconductor device that includes two switches integrated in a common die to form a half-bridge block.
Many power applications use half-bridge arrangements to manage the flow of current. For example, in DC-DC converters such as buck converters a half-bridge arrangement is connected between the line and ground, and is operated to control the supply of current to an output element such as an output capacitor.
In a conventional application, typically, two discreet, silicon-based vertical conduction power MOSFETs are series connected to form a half-bridge. The use of two devices consumes more board space, and because typically the devices are packaged separately, the use of two discreet devices may introduce undesirable parasitic resistance, inductance and capacitance into the circuit.
While theoretically two silicon-based power semiconductor devices may be integrated to form a half-bridge in a common semiconductor die to overcome some of the drawbacks noted above, there are practical disadvantages to doing so. For instance, it is difficult to integrate two vertical conduction type devices due to the fact that the power electrodes of silicon-based vertical conduction devices are on the opposite surfaces of the semiconductor die. Moreover, for the same current carrying capability, using lateral type devices consumes more die area than a vertical conduction device, thereby rendering such an option commercially undesirable.